Genetic risk for development of alcoholism in humans has been shown to be related to insensitivity to the initial effects of ethanol or to the development of acute tolerance to ethanol. This project utilizes rats that have been selectively bred for insensitivity or sensitivity to the initial effects of ethanol as a model of this phenomenon in humans. The project seeks to identify the genes responsible for this response in rats, to compare these results with similar studies in other rat selection studies and in mice to predict which genes may be responsible for the genetic risk factors in humans. The research utilizes methods of Quantitative Trait Loci (QTL) determination to locate these genes within the genome of the rat. Other breeding (development of congenic strains) and molecular biological methods are then used to focus on a narrower region of the genome in which these genes reside. This will allow the identification of the genes and show that they are responsible for a portion of the response to ethanol in the whole animal. This information is then applied to studies in humans to predict where genes will be found that influence the risk of development of alcoholism in humans. Development of prevention or treatment strategies will then be possible.